Lacy Bracken Fern

Pteridium aquilinum var. caudatum, or Pteridium caudatum

lacy bracken fern

Lacy bracken fern, photographed at Yamato Scrub Natural Area, Boca Raton, Palm Beach County, in March 2017.

What makes lacy bracken fern good, also makes it bad. It forms really dense patches, which provide cover for myriad small animals and birds. But those dense patches can be invasively dense. The fiddleheads are a delicacy for some folk, but they're also poisonous. Carcinogenic, even.

This is one of two subspecies, or varieties of bracken fern found in South Florida. To the science community it's variously known as Pteridium caudatum or P. aquilinum var. caudatum. Take your pick. Either way, it's a Florida native that's found south of Brevard County on the Atlantic side and Citrus County on the Gulf. Florida is the only state in the union where it grows, but its natural range extends through Bermuda, the Caribbean, Mexico, Central America and South America to Colombia and Peru.

The other variety of bracken fern found in South Florida is tailed bracken fern, P. aquilinum var. pseudocaudatum. There are by some counts as many as five varieties of bracken fern in the world, all generally considered as part of one species. It is said to be the most abundant of all ferns and one of the most widespead of all plants.

Lacy bracken fern and tailed bracken fern are fairly easy to tell apart, even to an untrained eye. The foliage on lacy bracken fern is much finer than it is on tailed bracken fern. Lacy bracken fern is also much taller, capable of hitting six feet, according to the Institute for Regional Conservation and 12 feet, according to the University of Florida. Tailed bracken fern pretty much tops out at 4 feet. And from what we've seen, the thickets lacy bracken fern form are much denser than tailed bracken fern. Touch the two plants and you'll notice another difference. Lacy bracken fern has a plastic feel to it because of small, stiff hairs that grow under the leaflets. Tailed bracken fern lacks those hairs and has a totally different feel to it.

Otherwise, the two cousins are pretty much the same: both arise from a single, woody stem that branches near the top, with triangular shaped fronds. Both also spread from underground stems, called rhizomes, that put out new shoots as they creep along. One word we've seen associated with lacy bracken fern is invasive, even within its natural range. It grows and spreads rapidly in part because of those rhizomes and in part because, like all ferns, it reproduces by spores that get dispersed by wind. The plant will colonize a newly open site and quickly take over and crowd out other plants from growing there. And if a fire strikes the same site, lacy bracken fern's rhizomes are deep enough to survive and repopulate the area. The flip side of that is the cover that lacy bracken fern provides birds and other small animals.

Lacy bracken fern will take to a variety of habitats — barrens, pine woodlands, the edges of forests. It will grow in dryer places but it will also take to wetlands. It will grow in full sun but also shade. Generally speaking, bracken fern is an extremely utilitarian plant, used as food, medicine and as a raw material for manufacturing glass, for example. And more. But it's also poisonous and has one cancer-causing agent — ptaquilosides.

Lacy bracken fern is a member of Dennstaediaceae, the bracken fern family. Other common names: southern bracken, southern bracken fern.

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Published by Wild South Florida, PO Box 7241, Delray Beach, FL 33482.

Photographs by David Sedore. Photographs are property of the publishers and may not be used without permission.